Organic derivatives of phosphonic acids and method of preparing the same



Patenteci Get. 6, 1953 UNITED STATES PATENT OFFICE ORGANIC DERIVATIVES OF PHOSPHONIC ACIDS AND METHOD OF PREPARING THE SAME Hans Z. Lecher, Plainfield, and Erwin Kuh, New Brunswick, N. J., assignors to American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing. Application August 2, 1952, Serial No. 302,406

18 Claims. 1

in-part, we described certain substituted diethyl- Y enephosphondiamides. We have now found that other compounds of the same general class have similar properties.

The compounds of the present invention, in contrast to those of the prior art, are N,N'- dialkylenimides of phosphonic acids which may be illustrated by the following general formula:

CH2 N/ R 0 al R CH2 N l R \R in which R is selected from the group consisting of hydrogen and lower alkyl radicals and R is selected from the group consisting of alkyl, alkenyl, cycloalkyl and aryl radicals.

The compounds of the present invention because of the reactive ethylenimine groups are useful as new textile chemicals and may be polymerized to form new plastics. However, it is surprising that the compounds of the present invention which contain the highly reactive ethylenimine ring are so stable that they may be also used as pharmaceuticals.

The compounds of this invention are prepared by starting with a phosphonyl chloride or bromide such as, for example, ethanephosphonyl dichloride; beta-chloroethanephosphonyl dichloride; 2,2 -dimethylethenephosphonyl dichloride; butanephosphonyl dichloride; cyclohexanephosphonyl dichloride; benzenephosphonyl dichloride; 4-methylbenzenephosphonyl dichloride; -chlorobenzenephosphonyl dichloride; 2-naphthalenephosphonyl dichloride; 2-thiophenephosphonyl dichloride; and the like. These phosphonyl dihalides are reacted with two molecular equivalents of an ethylenimine compound which may contain one or more substituents on a ring carbon atom to produce the desired compound. This latter reaction may be illustrated by the following equation:

in which X is halogen and R and R are as defined above.

The ethylenimine compound may be, for example, ethylenimine itself or a C-substituted ethylenimine such as 2-methylethylenimine; 2-ethylethylenimine; 2,2-dimethylethylenimine; 2-propylethylenimine; 2,2-diethylethylenimine; 2-hexylethylenimine; 2-ethyl-2-phenylethyleni mine; 2-propyl-2-phenylethylenimine; 2-phenyl ethylenimine; etc. The ethylenimine intermediates may be prepared by known procedures such as treatment with sodium hydroxide of the corresponding 2-haloethylamines or the sulfuric esters of the corresponding z-hydroxyethylamines.

The reaction to prepare the compounds of the present invention is preferably carried out in an inert organic solvent such as benzene, ether, dioxane, ethylene dichloride, and the like. It is necessary to have present as an acid acceptor a tertiary amine such as triethylamine or pyridine. With the more stable phosphonic chlorides the reaction can also be carried out in aqueous solution and under these circumstances, the acid acceptor may be an alkaline substance such as an alkali metal hydroxide or carbonate or bicarbonate. Isolation of the product from organic medium may be accomplished by filtration of the tertiary amine hydrohalide and crystallization from the organic solvent or by evaporation of the organic solvent. If prepared in aqueous medium, some members may be isolated by direct filtration. Others must be extracted from the aqueous medium with an organic solvent and subsequent evaporation of the organic solvent. The proby crystallization from ether.

cedure will vary with the individual members according to their solubility properties. i

The reaction is generally carried out at a temperature within the range of C. to about 80 C. At this temperature range the reaction is generally complete within a period of several minutes to several hours.

The following examples illustrate the preparation of representative phosphonic acid diamides of the present invention. All parts are by weight unless otherwise indicated.

EXAMPLE 1 N ,N diethylenebenzenephosphovtdiamide chloride is filtered off and the cake washed with dry benzene several times. The dry salt cake amounts to about 88% of the theoretical.

From the filtrate, the benzene is removed at low temperature in a vacuum. The viscous residue is distilled in a point is 117 to 120 C. at 0.2 mm. of mercury. It crystallizes spontaneously and may be recrystallized from very little benzene to obtain it as colorless plates with the melting point '75-'76.5 C., readily soluble in water, sparingly in acetone.

EXAMPLE 2 N ,N diethylenethcm eplhosphowdiamide A solution of 23 parts of ethanepho'sphonyl'dichloride in '44 parts of dry benzene is added to a solution of 32 parts of triethylamine and 14 parts of ethylenimine in l10'parts of dry benzene at a temperature between 5 and C. The triethylamine hydrochloride is removed by filtration and the benzene distilled off from the filtrate under reduced pressure. The'oily residue is fractionated in a vacuum and the product collected at 76-80 C. at 0.8 mm. Hg.

EXAMPLE 3 N ,N -diethylenecycldhexanephosphohdiamide CHr-CH: CH2

Hz a

A solution of 20.1 parts of cyclohexanephosphonyl dichloride in 45 parts of dry benzene is added gradually at 610 C. to a solution of 8.6 parts of ethylenimine and 22.2 parts of triethylamine in 135 parts of dry benzene. Triethylamine hydrochloride is filtered off, and benzene is removed from the filtrate by distillation under reduced pressure. The solid residue is purified Yield, 8.? parts;

melting point 64-'66 C. 7

high vacuum. The boiling EXAMPLE 4 N ,N -diethyZene-p-toluenephosphondiamide on, i 0 H2 2 A solution of 10.4 parts or p-toluenephosphonyl dichloride in 45 parts of dry benzene is added slowly at '5-10 C. to a solution of 4.3 parts of ethylenimine and 11.1 parts of triethylamine in 45 parts of dry benzene. The resulting triethylamine hydrochloride is filtered off and benzene is removed from the mother liquor by distillation under reduced pressure. The residual oil solidifies on cooling and is purified by several 'cry'stalli'zations from ether, yielding 3.5 parts of the desired product, melting point 56-57 C.

EXAMPLE 5 N,N' diethylene p chlorobenzenephosphondiamide CH2. i

To a solution of 8.6 parts of ethylenimine and 20.2 parts of triethylamine in 88 parts of dry benzene is added with agitation 23 parts of p-chlorobenzenephosphonyl dichloride dissolved in 40 parts of dry benzene at 5-10 C. The triethylamine salt is filtered ofi from the mother liquor and the benzene is removed completely in a vacuum. An almost colorless viscous liquid remains which gradually solidifies to a crystalline mass.

EXAMPLE 6 N,N-diethylenenaphthalene-Z-phosphondiamide A solution of 25 parts of Z-naphthalenephosphonic acid in 110 parts of phosphorus oxychloride is added slowly with stirring to a mixture of 50 parts of phosphorus pentachloride and 110 parts of phosphorus oxychloride. The resulting slurry is heated slowly to C. and held at this temperature as long as hydrogen chloride is evolved. Excess phosphorus oxychloride is removed by distillation under reduced pressure, and the oily residue is fractionated to give 24 parts of Z-naphthalenephosphonyl dichloride, boiling point 142-143.5/0.048 mm. Hg. Melting point is approximately 55 C.

A solution of 24.5 parts of 2-naphthalenephosphonyl dichloride in 90 parts of dry benzene is added slowly at 610 C. to a mixture of 9 parts of ethylenimine, 21.2 parts of triethylamine and 90 parts of dry benzene. Triethylamine hydrochloride is filtered off and solvent removed from the mother liquor by distillation under reduced pressure. The crude product is purified by crystallization from benzene, melting point"93-94' C. EXAMPLE '7 MN diethylene 2 methyl 1 propane-1- phosphondiamide To 7,468.95 parts of anhydrous benzene ina 2 0 liter flask fitted with a stirrer and cooling bath, is added 2080 parts of phosphorus pentachloride. The stirred mixture is cooled to within a few degrees of the freezing point of benzene and 600 parts of isobutylene is bubbled into the mixture at a rate slow enough to keep the reaction temperature at about 12 C. while the flask is immersed in an ice-salt bath. This requires 30 to 45 minutes. To the above thick slurry of the addition product 500 parts of phosphoric anhydride is slowly added. The mixture is then heated on a steam bath at 60 C. with stirring. The solution is filtered to remove the small amount of unreacted phosphorus pentoxide and the filtrate subjected to vacuum distillation to remove benzene, hydrogen chloride and phosphorus oxyohloride. This is continued until the vapor temperature reaches 80 C. at 30-40 mm. The residue is then subjected to vacuum distillation. The 2-methyll-propene-l-phosphonyl dichloride is a colorless liquid having a boiling point of 99-101 C. at 17 mm.

-A solution of 17.3 parts of 2-methyl-1-propenel-phosphonyl dichloride in 45 parts of dry benzene is added slowly at 6-10 C. to a mixture of 8.6 parts of ethylenimine, 22.2 parts of triethylamine and 135 parts of dry benzene. Triethylamine hydrochloride is filtered off and the solvent removed from the mother liquor by distillation under reduced pressure. The residual oil is purl fled by fractionation. The boiling point is 96 C. at 0.7 mm. Hg. Yield, 5.5 parts. i

We claim:

1. Compounds of the formula:

group having the general in which R is a member of the group consisting of hydrogen and lower alkyl radicals and R is selected from the group consisting of alkyl, alkenyl, cycloalkyl and aryl radicals.

2. Compounds of the group having the general formula:

in which R is a monocyclic aryl radical.

3. N,N' diethylene benzenephosphondiamide having the formula:

4. N,N' diethylenethanephosphondiamide, having the formula:

5. N,N' diethylenecyclohexanephosphondiamide having the formula:

1 1 CH2 ar-M H2 2 '7. N,N' diethylene p chlorobenzenephosphondiamide having the formula:

8. N,N' diethylenenaphthalene 2 phosphondiamide having the formula:

w) t \m.

9. N,N' diethylene 2 methyl 1 propenel-phosphondiamide having the formula:

10. A method of the formula:

preparing compounds having in which X is halogen of the atomic number between 17 and 35 and R is as defined above with a. compound having the formula:

in which R is as defined above, and recovering said compound therefrom.

cameras aryl radical which the forin which R. is a monocyclic comprises reacting. a compound having mula-z in which X is halogen of the atomic number between 17 and 35 and R isas defined above, with ethylenimine, and recovering said compound therefrom.

12. A method of preparing N;N'-di'ethy1enebenzenephosphondiamide which comprises reacting benzenephosphonyl dichloride with ethylenirnine in an inert organic solvent in the presence of a tertiary amine and recovering said compound therefrom.

13. A method of preparing N,N-diethylenethanephosphondiamide which comprises reacting ethanephosphonyl dichloride with ethylenirnine in an inert organic solvent inv the presence of a tertiary amine and recovering said compound therefrom. c

14. A method of preparing N,N'-diethylenecyciohexa'nephosphondiamide: which comprises reacting. cyclohexanephosphonyl dichloride with ethylenimine. in an inert organic solvent in the presence of. a" tertiary amine and recovering. said compound therefrom.

15 A method: of preparing N ,N -diethylene-ptoluenephosphondiamide' which comprises reacting: p -toluenephosphonyl dichloride with ethylenimineiin-an inert organic solvent. in the presence-of a tertiary; amine and recovering said com pound therefrom.

1.6:.v A,. method of preparing N,N -diethylenepchlorobenzenephosphondiamide which comprises reacting p-chlorobenzenephosphonyl dichloride with ethylenimine in an inert organic solvent in the presence of a tertiaryamine; and recovering said com-pound therefrom.

17:. A method. of preparing N-,N'-diethylenenaphthalene 2 --phosphondiamide which" comprises: reacting naphthalene-z-phosphonyl dichloride with ethylenimine in an inert organic solvent in the presence of a tertiary amine and recovering saidv compound. therefrom.

18. Amethod of. preparing N-,N--diethylene-2- methyl l --propene:-- l -phosphondiamide which comprises reacting 2-methyl-1propene-1-phosphonyl. dichloride with ethylenimine in an inert organic solvent in the presence ofatertiary amine and recovering said compound therefrom;

HANS Z. LE'CI-IER.

No references cited. 

1. COMPOUNDS OF THE GROUP HAVING THE GENERAL FORMULA: 